One more question. How can he revert back to Windows 7? He wants to re-install so he can dual-boot it with Windows 7.

In Windows 8, put the mouse down to the bottom left start screen corner and Right Click > Disk Management

Select C: > Right click > Shrink Volume

Choose the size he wants the partition for 7 to be and hit Shrink

Once it has partitioned, it will be Unpartitioned Space, to avoid confusion with any other drives etc, I find it best to Right Click that unpartitioned space and choose Format > give it a name like "New 7" something easy to spot / remember during HDD selection in setup and choose Quick Format

Once it has formatted, just boot from the 7 DVD as normal and choose that new partition to install onto

The end result will be a choice of 7 or 8 to boot into when he powers on the machine

In Windows 8, put the mouse down to the bottom left start screen corner and Right Click > Disk Management

Select C: > Right click > Shrink Volume

Choose the size he wants the partition for 7 to be and hit Shrink

Once it has partitioned, it will be Unpartitioned Space, to avoid confusion with any other drives etc, I find it best to Right Click that unpartitioned space and choose Format > give it a name like "New 7" something easy to spot / remember during HDD selection in setup and choose Quick Format

Once it has formatted, just boot from the 7 DVD as normal and choose that new partition to install onto

The end result will be a choice of 7 or 8 to boot into when he powers on the machine